Sequential injection immunoassay for human bone morphogenic protein-7 using an immunoreactor immobilized with anti-human bone morphogenic protein-7 antibody-CdSe/ZnS quantum dot conjugates

摘要

The detection of human bone morphogenic protein-7 (BMP-7) was achieved using a sequential injection immunoassay (SUA) system. The SUA system is based on the binding between BMP-7 and anti-human BMP-7 (AbBMP7)-CdSe/ZnS quantum dot (QP) conjugates immobilized onto a glass disk or an optical fiber, using fluorescence detection at excitation and emission wavelengths of 470 nm and 580 nm, respectively. The AbBMP7-QD conjugates were prepared by conjugating anti-human BMP-7 antibody (AbBMP7) to hydrophilic CdSe/ZnS core/shell quantum dots (QDs). The SUA system was fully automated using software written in the LabVIEW~(TM) development environment. The analytical performance of the SUA system was characterized with a number of variables such as carrier flow rate and elution buffer. Under partially optimized operating conditions, the SUA system had a linear calibration graph at up to 10.0ngmL~(-1) BMP-7 (R~2≥ 0.975) and a sample frequency of two samples per hour. The SUA system with an optical fiber immunosensor was used to detect and quantify BMP-7 in spiked real samples obtained from a biological process with recoveries in the range of 95-102%.